Commit Message

Add a compat property for older machine types. When this is used (via
-M pc-0.13, for example), the new flow control mechanisms will not be
used. This is done to keep migration from a machine started with older
type on a pc-0.14+ qemu to an older machine working.
The property is named 'flow_control' and defaults to on.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
hw/pc_piix.c | 16 ++++++++++
hw/virtio-pci.c | 2 +
hw/virtio-serial-bus.c | 77 +++++++++++++++++++++++++++++++++++++++++-------
hw/virtio-serial.h | 12 +++++++
4 files changed, 96 insertions(+), 11 deletions(-)